In order to reduce deposit formation, detergents and dispersants are known to assist in maintaining reduced amounts of deposits on engine components. The lubricant industry has a number of tests used to evaluate a lubricant's ability to handle deposits and sludge including the Sequence VG, Sequence IIIG, TDi, Cat 1N, and OM501LA.
With recent changes to engine specifications there is an increasing demand on the lubricant to reduce deposits. For instance, the new ILSAC GF-5 specification requires a 4.0 weighted piston deposit rating in the Sequence IIIG (vs. 3.5 for GF-4).
International Application WO2007/128740 (published 15 November, 2007) discloses the use of one or more poly (hydroxycarboxylic acid) amide salt in combination with one or more antiwear additive. Such compositions were useful for dispersing preformed sludge deposits.
International Application WO2009/053413 (published 30 Apr. 2009) and European Patent Application EP2055729 (published 6 May 2009) both disclose compositions comprising base oil and one or more poly (hydroxycarboxylic acid) amide salt derivatives. The lubricating oils were useful for reducing wear and friction.
International Application WO2009/156393 (published 30 Dec. 2009) discloses a lubricant with one or more poly (hydroxycarboxylic acid) amide salt with TBN less than 10. The Lubricant ameliorated piston deposits in fired engine tests such as the TU5 and Sequence IIIF.
International Application WO2010/012756 (published 4 Feb. 2010) and US Patent Application US2010/0024286 (published 4 Feb. 2010) both disclose a fuel composition comprising a fuel and one or more poly (hydroxycarboxylic acid) amide salts. Such fuels offered benefits such as improved lubricity by HFRR, Improved inlet valve deposits in fired engine tests and improved sludge dispersancy in the Sequence VG engine test.
International Application WO2010/014678 (published 4 Feb. 2010) discloses a poly (hydroxycarboxylic acid) amide salt derivative wherein the anionic portion of the salt does not contain sulphur. The molecules described showed lower phosphorus volatility in Selby NOACK testing in fully formulated fluids than similar materials that had sulphur-containing anions.
International Application WO2010/015706 (published 11 Feb. 2010) discloses a lubricant comprising base oil, a poly (hydroxycarboxylic acid) amide salt and one or more detergents. The composition is useful for dispersing preformed sludge deposits.
International Application WO2010/012763 (published 4 Feb. 2010) and US Patent Application US2010/0024287 (published 4 Feb. 2010) both disclose a fuel composition comprising a fuel and one or more poly (hydroxycarboxylic acid) derivative having a terminal acid group. The fuels of the disclosed composition demonstrated some improved lubricity characteristics.